Re: ic pump
A *little* foam is normal especially if the truck is hot. However, a lot of foam is not. Excessive foam is a sign that there is air trapped in the system. Trapped air will greatly reduce the efficiency of your intercooler. Air won't remove heat as quickly as water will. Ensuring that coolant is routed in such a way to keep air from getting trapped in the first place and running the pump with the cap off while topping the system off is the only way to eliminate this problem.
Bottom line is a cool motor is a happy motor. The higher your engine temperatures are, the more likely you are to experience detonation. Detonation hampers performance in two ways. First, the ECM will retard the timing anytime it detects it (unless you have a KB "kaboom" chip that doesn't have ANY spark retard :roll: ) via the knock sensor on the back of the motor. The other way detonation hampers performance is putting connecting rods through the oilpan... Therefore, preventing it is VERY important if you own a syty as our motors WILL NOT tolerate knock for long.
There are no drawbacks whatsoever from having your IC pump run all the time unless you live in a state that has emissions testing. In that case, disabling it from service during such testing will help you pass the "sniffer". If you have went the extra mile and installed a 160 degree thermostat, going back to the stock 195 degree one will help as well (remember, cooler is better). Lowering the fuel pressure if you have an Adjustable Fuel Pressure Regulator (AFPR) is another "trick" to passing.
With regards to the factory mindset, that is anybody's guess. Why install an inaccurate boost gauge in a turbocharged vehicle? Why use metal lines to circulate coolant that are attached to the top of a hot motor? Why have a wire triggers the starter in such close proximity to an insanely hot heat source? And the list gose on and on... It would *seem* that the pump coming on at the higher operating temps would be beneficial as that is when detonation would be most likely to occur. That doesn't do you any favors when the temperature is rising up to that temperature however.